1 // SPDX-License-Identifier: GPL-2.0
3  * Coherent per-device memory handling.
10 #include <linux/dma-direct.h>
11 #include <linux/dma-map-ops.h>
23 static inline struct dma_coherent_mem *dev_get_coherent_memory(struct device *dev)  in dev_get_coherent_memory()
25 	if (dev && dev->dma_mem)  in dev_get_coherent_memory()
26 		return dev->dma_mem;  in dev_get_coherent_memory()
30 static inline dma_addr_t dma_get_device_base(struct device *dev,  in dma_get_device_base()
33 	if (mem->use_dev_dma_pfn_offset)  in dma_get_device_base()
34 		return phys_to_dma(dev, PFN_PHYS(mem->pfn_base));  in dma_get_device_base()
35 	return mem->device_base;  in dma_get_device_base()
46 		return ERR_PTR(-EINVAL);  in dma_init_coherent_memory()
50 		return ERR_PTR(-EINVAL);  in dma_init_coherent_memory()
55 	dma_mem->bitmap = bitmap_zalloc(pages, GFP_KERNEL);  in dma_init_coherent_memory()
56 	if (!dma_mem->bitmap)  in dma_init_coherent_memory()
59 	dma_mem->virt_base = mem_base;  in dma_init_coherent_memory()
60 	dma_mem->device_base = device_addr;  in dma_init_coherent_memory()
61 	dma_mem->pfn_base = PFN_DOWN(phys_addr);  in dma_init_coherent_memory()
62 	dma_mem->size = pages;  in dma_init_coherent_memory()
63 	dma_mem->use_dev_dma_pfn_offset = use_dma_pfn_offset;  in dma_init_coherent_memory()
64 	spin_lock_init(&dma_mem->spinlock);  in dma_init_coherent_memory()
74 	return ERR_PTR(-ENOMEM);  in dma_init_coherent_memory()
82 	memunmap(mem->virt_base);  in _dma_release_coherent_memory()
83 	bitmap_free(mem->bitmap);  in _dma_release_coherent_memory()
87 static int dma_assign_coherent_memory(struct device *dev,  in dma_assign_coherent_memory()
91 		return -ENODEV;  in dma_assign_coherent_memory()
93 	if (dev->dma_mem)  in dma_assign_coherent_memory()
94 		return -EBUSY;  in dma_assign_coherent_memory()
96 	dev->dma_mem = mem;  in dma_assign_coherent_memory()
102  * is asked for coherent memory for this device.  This shall only be used
103  * from platform code, usually based on the device tree description.
108  * device_addr is the DMA address the device needs to be programmed with to
115  * be declared per device.
117 int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,  in dma_declare_coherent_memory()
133 void dma_release_coherent_memory(struct device *dev)  in dma_release_coherent_memory()
136 		_dma_release_coherent_memory(dev->dma_mem);  in dma_release_coherent_memory()
137 		dev->dma_mem = NULL;  in dma_release_coherent_memory()
141 static void *__dma_alloc_from_coherent(struct device *dev,  in __dma_alloc_from_coherent()
150 	spin_lock_irqsave(&mem->spinlock, flags);  in __dma_alloc_from_coherent()
152 	if (unlikely(size > ((dma_addr_t)mem->size << PAGE_SHIFT)))  in __dma_alloc_from_coherent()
155 	pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);  in __dma_alloc_from_coherent()
164 	ret = mem->virt_base + ((dma_addr_t)pageno << PAGE_SHIFT);  in __dma_alloc_from_coherent()
165 	spin_unlock_irqrestore(&mem->spinlock, flags);  in __dma_alloc_from_coherent()
169 	spin_unlock_irqrestore(&mem->spinlock, flags);  in __dma_alloc_from_coherent()
174  * dma_alloc_from_dev_coherent() - allocate memory from device coherent pool
175  * @dev:	device from which we allocate memory
181  * This function should be only called from per-arch dma_alloc_coherent()
182  * to support allocation from per-device coherent memory pools.
187 int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size,  in dma_alloc_from_dev_coherent()
202 	if (mem && vaddr >= mem->virt_base && vaddr <  in __dma_release_from_coherent()
203 		   (mem->virt_base + ((dma_addr_t)mem->size << PAGE_SHIFT))) {  in __dma_release_from_coherent()
204 		int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;  in __dma_release_from_coherent()
207 		spin_lock_irqsave(&mem->spinlock, flags);  in __dma_release_from_coherent()
208 		bitmap_release_region(mem->bitmap, page, order);  in __dma_release_from_coherent()
209 		spin_unlock_irqrestore(&mem->spinlock, flags);  in __dma_release_from_coherent()
216  * dma_release_from_dev_coherent() - free memory to device coherent memory pool
217  * @dev:	device from which the memory was allocated
221  * This checks whether the memory was allocated from the per-device
227 int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr)  in dma_release_from_dev_coherent()
237 	if (mem && vaddr >= mem->virt_base && vaddr + size <=  in __dma_mmap_from_coherent()
238 		   (mem->virt_base + ((dma_addr_t)mem->size << PAGE_SHIFT))) {  in __dma_mmap_from_coherent()
239 		unsigned long off = vma->vm_pgoff;  in __dma_mmap_from_coherent()
240 		int start = (vaddr - mem->virt_base) >> PAGE_SHIFT;  in __dma_mmap_from_coherent()
244 		*ret = -ENXIO;  in __dma_mmap_from_coherent()
245 		if (off < count && user_count <= count - off) {  in __dma_mmap_from_coherent()
246 			unsigned long pfn = mem->pfn_base + start + off;  in __dma_mmap_from_coherent()
247 			*ret = remap_pfn_range(vma, vma->vm_start, pfn,  in __dma_mmap_from_coherent()
249 					       vma->vm_page_prot);  in __dma_mmap_from_coherent()
257  * dma_mmap_from_dev_coherent() - mmap memory from the device coherent pool
258  * @dev:	device from which the memory was allocated
264  * This checks whether the memory was allocated from the per-device
267  * Returns 1 if @vaddr belongs to the device coherent pool and the caller
271 int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma,  in dma_mmap_from_dev_coherent()
282 void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size,  in dma_alloc_from_global_coherent()
325  * Support for reserved memory regions defined in device tree
337 static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev)  in rmem_dma_device_init()
339 	if (!rmem->priv) {  in rmem_dma_device_init()
342 		mem = dma_init_coherent_memory(rmem->base, rmem->base,  in rmem_dma_device_init()
343 					       rmem->size, true);  in rmem_dma_device_init()
346 		rmem->priv = mem;  in rmem_dma_device_init()
348 	dma_assign_coherent_memory(dev, rmem->priv);  in rmem_dma_device_init()
353 				    struct device *dev)  in rmem_dma_device_release()
356 		dev->dma_mem = NULL;  in rmem_dma_device_release()
366 	unsigned long node = rmem->fdt_node;  in rmem_dma_setup()
369 		return -EINVAL;  in rmem_dma_setup()
372 	if (!of_get_flat_dt_prop(node, "no-map", NULL)) {  in rmem_dma_setup()
373 		pr_err("Reserved memory: regions without no-map are not yet supported\n");  in rmem_dma_setup()
374 		return -EINVAL;  in rmem_dma_setup()
379 	if (of_get_flat_dt_prop(node, "linux,dma-default", NULL)) {  in rmem_dma_setup()
382 		dma_reserved_default_memory_base = rmem->base;  in rmem_dma_setup()
383 		dma_reserved_default_memory_size = rmem->size;  in rmem_dma_setup()
387 	rmem->ops = &rmem_dma_ops;  in rmem_dma_setup()
389 		&rmem->base, (unsigned long)rmem->size / SZ_1M);  in rmem_dma_setup()
397 		return -ENOMEM;  in dma_init_reserved_memory()
404 RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup);